Fracture toughness values of solid wood, heat-treated wood and PEG impregnated wood.

Fracture toughness testing was carried out on solid wood, heat-treated wood and polyethylene glycol (PEG) impregnated wood.The main results are summarized as follows:(1) The load-displacement curves had very different patterns for solid wood, heat-treated wood and PEG impregnated wood.(2) The fracture toughness value of the heat-treated wood was equal or larger than that of the solid wood.(3) The fracture toughness value of the PEG impregnated wood was larger than those of the solid wood and the heat-treated wood.(4) The Young's modulus of the heat-treated wood was larger than that of the solid wood.(5) The Young's modulus of the PEG impregnated wood was smaller than that of the heat-treated wood.(6) The cumulative acoustic emission energy of PEG impregnated wood was very much smaller than those of the solid wood and heat-treated wood